Visual observations of sea birds in the Southern Ocean in the 1979-1980 summer

Abstract

Visual observations of sea birds in the Southern Ocean were carried out on board three ships during the austral summer of 1979-1980; two ships for exploratory fishing of krill, a factory ship SHINANO MARU and a trawler ORIENTO MARU, and one ship for the population census of minke whale, KYO MARU (a catcher). The surveyed area was south of 63°S between 0°E and 115°E in longitude. Ten minutes within a day were allocated for bird observations. The species and the number of sea birds observed in ten minutes were recorded on a data sheet which was a slightly modified standard recording card of SCAR prepared for this survey. The bird species that occurred in a wide longitudinal range were the breeders on the Antarctic Continent or on the adjacent island in austral summer, i. e. antarctic petrel, snow petrel, cape pigeon, and Wilson's storm petrel. Light-mantled sooty albatross and sooty shearwater that are breeding on the sub-Antarctic islands also occurred in a wide range; these two birds are highly pelagic in habit and often disperse south to the edge of the pack ice in summer.